Key takeaways
Xifaxan (rifaximin) and Alinia (nitazoxanide) are both prescription medications used to treat different types of diarrhea, but they work in different ways and treat different causes. Xifaxan is a rifamycin antibiotic that treats travelers' diarrhea caused by *E. coli*, irritable bowel syndrome with diarrhea (IBS-D), and prevents hepatic encephalopathy (HE) in adults. It works by stopping bacteria in the gut from making proteins they need to survive. On the other hand, Alinia is an antiprotozoal medication that treats diarrhea caused by the parasites *Giardia lamblia* and *Cryptosporidium parvum*. It works by blocking a protein that these parasites need to grow. Xifaxan is taken 2 to 3 times a day, while Alinia is taken 2 times a day for 3 days. Xifaxan is available only as tablets, whereas Alinia comes in both tablets and an oral suspension. Common side effects of Xifaxan include swelling, dizziness, and fatigue, while Alinia can cause headaches and a change in urine color.
